KCTF2021 第二题南冥神功 wp-CTF对抗-看雪-安全社区|安全招聘|kanxue.com

KCTF2021 第二题南冥神功 wp

发表于: 2021-5-12 10:08 5183

KCTF2021 第二题南冥神功 wp

neilwu

2021-5-12 10:08

5183

迷宫、深度优先搜索

其中v10是求解关键，即走图path

根据深度优先搜索对每一个可能的分支路径深入到不能再深入为止，而且每个节点只能访问一次即获得路径
path坐标

path[]

根据path可以逆推出falg

图片描述

sub_4AF840((int)&dword_4B8860, "Input your code: ");

sub_4B0AB0((int)&dword_4B8680, v25);

if ( strlen(v25) <= 48 )

sub_4AF840((int)&dword_4B8860, "Input your code: ");

sub_4B0AB0((int)&dword_4B8680, v25);

if ( strlen(v25) <= 48 )

v13 = &aS_1[10 * v21 + v9];
 
aS_1
 
S010010011
1100100100
0010111110
0110100100
0010010011
1101110101
0011110101
0110010101
0001001100

v13 = &aS_1[10 * v21 + v9];

aS_1

S010010011

1100100100

0010111110

0110100100

0010010011

1101110101

0011110101

0110010101

0001001100

v7 = (v4 + v5 / 6) % 6;

v8 = v5 + v4;

v9 = v22;

v20 = v7;

v10 = 5 - v8 % 6;

for ( i = 0; ; i = 1 )
{

  switch ( v10 )

  {

    case 1:

      ++v9;

      break;

    case 2:

      v17 = (v21++ & 1) == 0;

      v9 += v17;

      break;

    case 3:

      v12 = (v21++ & 1) != 0;

      v9 -= v12;

      break;

    case 4:

      --v9;

      break;

    case 5:

      v19 = (v21-- & 1) != 0;

      v9 -= v19;

      break;

    default:

      v18 = (v21-- & 1) == 0;

      v9 += v18;

      break;

  }

  if ( v9 > 9 )

    break;

  if ( v21 > 8 )

    break;